Effect of Plastic Deformation on the Structure and Magnetic Properties of Hull Steel

The effect of plastic deformation on the structure, residual stresses and magnetic characteristics of hull steel 20GN is studied. The microstructure of deformed specimens is determined in directions transverse and longitudinal to the direction of the deformation using optical and electron microscopes. Histograms of the distribution of the misorientation angles inside grains are plotted and crystallization maps are constructed. The magnetic characteristics are measured in a closed magnetic circuit with the help of a Remagraph C-500 hysteresisograph and attached magnetic transducers (AMT). The ranges of plastic deformation in which the behavior of the magnetic parameters changes with growth of the strain are determined experimentally as well as their interrelation with the variation of the structure and of the residual stresses. The results obtained may be helpful for developing methods of assessment of the stress-strain state of articles from steel 20GN undergoing plastic deformation in service.